To promote the healing process of a fragmented or split bone, it has been known to exert an external force on the bone fragments by tightly clamping them together. For doing so, flexible elongated members such as wires or threads can be used which are tensioned around the bone fragments.
For example, during chest or heart surgery, it is known to split the sternum into two halves by means of a longitudinal section. The sternum halves need then to be joined again, for example, by arranging a wire around the sternum halves in a circumferential manner, so as to surround a cross-sectional area thereof. The cross-sectional area extends typically transverse to the longitudinal section through the sternum. Afterwards, the wire is tensioned by connecting and twisting the free ends thereof.
Furthermore, it has been known to arrange protector pads between the wire and an adjacent surface of the respective bone fragments. The protector pads avoid that the wire cuts into the bone surface when tensioning it, thus causing damage to the bone.
U.S. Pat. No. 6,287,307 generally discloses an apparatus and a method for clamping the split bone sections of a sternum. For doing so, protector pads in form of sternal plates are arranged in opposite configuration at the split sternum halves. The sternum plates are provided with spikes which are driven into outer side surfaces of the sternum halves by means of a forceps. The sternum plates are hence directly fixed at the bone fragments in a first step. Afterwards, a surgeon can guide and tension a circumferential wire around the sternum plates and the bone fragments arranged therebetween.
U.S. Pat. No. 8,597,327 generally discloses a method and apparatus for securing a fractured or sectioned sternum by means of a flexible member construct forming circumferential loops around the sternum halves. In addition, protector members are provided for guiding and fixing said flexible member construct around the sternum halves.
PCT Appin. No. WO 2012/027025 generally discloses a method for closing a sternum with help of adhesives. The adhesives may also be applied in contact regions between the sternum halves and an additionally provided circumferential wire to form a protective layer similar to the known protector pads.
There is a need for a surgical instrument for fixing bone fragments which can be reliably operated and limits unnecessary damage to the bone fragments.